Updated 11:50 a.m. | It started as a race to choose the next ranking member of the Energy and Commerce Committee; it could ultimately end as a referendum on the status quo.

When House Democrats finally settle the score this week, their choice between Reps. Frank Pallone Jr. of New Jersey and Anna G. Eshoo of California could send a strong message about how deeply members still hew to the seniority system.

And in a caucus growing increasingly antsy over the stasis at the leadership table, this ranking member election could be the closest thing to an up-or-down vote on Minority Leader Nancy Pelosi that members get for the next two years.

Pelosi, who has repeatedly endorsed her close friend Eshoo, is expected to run unopposed for a sixth full term as the House’s top Democrat.

Lawmakers will not say so publicly, but many of them think that if Eshoo loses, it will be because she became a casualty of greater frustrations within the caucus.

The fight sparked by California Democrat Henry A. Waxman's retirement announcement in January became so dramatic because there was never a clear front-runner or an easy choice. Stakeholders agree Pallone and Eshoo’s policy positions are nearly identical, and their legislative records are unblemished.

So members were forced to consider other factors: Who called them first to ask for their vote? Who gave them money in a tough re-election bid? Who has always been their friend? Eshoo, the No. 5 Democrat on the panel, has cast herself as a champion for colleagues who believe the seniority system should never be, as she said back in February, "sacrosanct."

"With almost 50 percent of our caucus members being members of the Democratic Caucus with six years or less under their belts, then maybe for the seniority question, attitudes are changing," said Rep. Raúl M. Grijalva, D-Ariz., who in 2013 lost to a more senior member in a bid to be ranking member on Natural Resources.

Pallone, the committee’s No. 3 Democrat, has appealed to the caucus’ longstanding deference to seniority. The Congressional Black Caucus is especially protective of what it dubs the "historic tradition" that has allowed its members to steadily climb up committee leadership ranks.

"When I first came here 10 years ago, the conversation among members was, 'Seniority mattered,'" said Rep. G.K. Butterfield, D-N.C., the CBC's likely chairman in the 114th Congress.

"As the years went on, the conversation became, 'Seniority is important, but not controlling.' Then the conversation was, 'Seniority is a factor.' And now the discussion among some is that seniority really should not be a determinant," he said. "That is not the direction I want our caucus to go."

Pelosi’s decision to insert herself into the race also was a turning point. It’s rare for leaders to take such strong public positions in gavel fights, and members and aides agree — no matter which candidate they support — the party leader is assuming some risk in coming out so strongly for her fellow Californian.

An Eshoo victory would show Pelosi’s influence remains strong as ever, while a loss could raise questions about Pelosi’s clout at a time when she is trying to hold a demoralized caucus together after a bruising election cycle.

“She is the Democratic leader and also Anna Eshoo’s best friend, so if anyone thought she wasn’t going to endorse her, they hit their head on the way to work," Thompson said. "There is not a single member of the Democratic Caucus who doesn’t want Nancy Pelosi’s support. There’s not one person who hasn’t come to her asking for her help.”

It's true there are plenty of people supporting Pallone who are and will remain loyal to Pelosi, and for them the vote isn’t anything more than a simple preference.

Thompson was articulating what many members — Eshoo and Pallone supporters alike — have said privately in dozens of interviews with CQ Roll Call since Pelosi sent out that first endorsement letter back in February, though Pelosi insists there is more to it than friendship.

“I’m very proud of Anna Eshoo,” the minority leader said at a news conference on Nov. 13. “I think sometimes in the course of our legislative lives, a person comes along who is a perfect fit to take us into the future. I think that is who she is.”

Both ranking member hopefuls are working overtime to shore up eleventh-hour support. Rep.-Elect Brad Ashford of Nebraska told CQ Roll Call that he’s already gotten calls from the candidates themselves, as well as from Pelosi and Minority Whip Steny H. Hoyer of Maryland, who is quietly but openly operating for Pallone.

And the sniping continues.

Team Pallone outed Eshoo for only giving money to vulnerable lawmakers who supported her ranking member bid; Team Eshoo hit back that Pallone only started giving money to everybody once the slot opened up.

Pallone's camp pointed out Eshoo formed a leadership PAC in March , a sign she only recently got serious about being a "team player"; Eshoo's backers have countered Pallone is hardly a paragon of sportsmanship, never making it a secret he'd rather be in the Senate.

Eshoo is likely to win phase one of the selection process and win the recommendation of the regional representatives, leaders, senior members and Pelosi appointments who make up the 50-pus-member Steering and Policy Committee. If a losing candidate receives more than 14 votes among that group, he or she can force a runoff among all the House Democrats. Should a candidate not receive that threshold, he or she can still appeal to supporters to demand a full caucus consideration: A letter with 50 signatures will do the trick. Neither of these requirements should be a problem for either candidate seeking a full caucus vote, which will come down to a razor-thin wire.

Lawmakers and aides say Pallone and Eshoo are neck-and-neck at this point; both candidates, of course, insist they have the whole thing locked up.